I know you feel differently, but the fact is that in almost every respect Autotrim is not automation in the same sense as AP and A/THR - it is simply a dumb load-balancing device and does not require the inputs that AP, A/THR and FD do.
Dozy,
I know it has been a long time since you have flown, but did you ever learn how to trim up an aircraft?
You seem to not appreciate the significance of trim in aircraft control, particularly, speed control. In the old days, before everything became automated, that was the foundation for getting an aircraft to behave. It is also one of the skills that can deteriorate with disuse.